As the Baby Brezza Bottle Washer Pro has a number of cleaning modes it will depend on the options you choose. The contents will only be sterilised if you use the Wash-Sterilise-Dry, Sterilise-Dry, or Sterilise Only options. If you have used any of these options the contents will remain sterile for up to 24 hours provided the lid is not opened.
If you use any of the Wash-Dry, Wash Only, or Dry only functions this will not sterilise your bottles. If you use any of these functions simply add more water to the clean water tank and then select either Wash-Sterilise-Dry, Sterilise-Dry or Sterilise Only.